The present invention relates to any type of machine-tool, machining station or centre or the like of the type comprising:
a support for the piece undergoing machining;
a machining head carrying a rotary spindle, to which there is connected in rotation a tool, said machining head being displaceable in three mutually perpendicular directions with respect to a fixed structure of the machine-tool;
a tool magazine comprising a plurality of seats designed to receive and support respective tools, and at least one protection wall, which separates the working area of the machining head from an external protected area.
Machines of the type referred to above are, for example, used for machining lines, for instance, production lines for engine parts for motor vehicles, such as cylinder heads. In this type of machine, the tool magazine, for instance, in the form of a rotary wheel carrying along its periphery a plurality of tool-bearing seats, is periodically supplied with new tools as replacements for tools that have previously been used, for example, on account of failure or wear, or also following upon the need to change the type of machining operation to be carried out. According to traditional techniques, the operation of replacing one or more tools in the corresponding positions in the tool magazine is performed manually. However, this operation is frequently somewhat inconvenient, on account of the limited spaces available around the magazine, and also entails safety problems for the operator.
The purpose of the present invention is to overcome the aforesaid drawbacks by enabling loading of a new tool into the tool magazine or unloading of a tool from the magazine with extremely simple, easy and fast operations and with total safety for the operator.
With a view to achieving the above purpose, the subject of the invention is a device for loading and unloading tools into/from the tool magazine of a machine-tool of the type referred to at the beginning of this description, characterized in that the aforesaid protection wall has an opening for access to the working area of the machining head, and in that said device further comprises an oscillating drawer having two walls that are set at an angle to one another and are mounted oscillating on said protection wall between a first position, in which one of said two walls of the drawer obstructs the access opening, and a second position, in which the other wall of the drawer obstructs the access opening, said drawer further comprising receiving and supporting means for a tool, which are arranged between the two aforesaid walls set at an angle to one another, in such a way that, in the aforesaid first position of the oscillating drawer, the aforesaid tool-bearing means are set on the outside of the protection wall, whereas, in the aforesaid second position, the aforesaid tool-bearing means are set on the inside of the protection wall.
Thanks to the above-mentioned characteristic, when the drawer is in its first position, the operator can load, conveniently and in maximum safety, a new tool that is to be loaded into the tool magazine, setting it on the aforesaid tool-bearing means. Once this operation has been carried out, the operator simply has to cause oscillation of the drawer into its aforesaid second position, so as to bring the new tool loaded on the inside of the protection wall, whilst safety of the operator always remains ensured, in so far as the access opening is in any case kept obstructed by the drawer. Once the new tool is on the inside of the protection wall, it is the machining head itself which displaces until it reaches the said new tool, so as to be able to pick it up, then to displace into a position corresponding to a position of the tool magazine in order to deposit the new tool thus picked up in said position in the magazine. In machines of the type described above, the movements of the machining head are of course controlled by an electronic control system. It is equally evident that the machining head is able to pick up a tool from the magazine and bring it onto the tool-bearing means of the oscillating drawer, after said means have been pre-set on the inside of protection wall in an empty condition. Once this operation has been performed, the operator from outside can bring the door back into its extracted position, so as to bring the tool deposited therein onto the outside of the protection wall, where it can be unloaded in complete safety. Of course, there is nothing to rule out the possibility of the machining head, after it has picked up a new tool from the drawer, using it immediately to carry out a machining operation. It is likewise evident that, in order to pick up a tool from the drawer, the machining head must have previously unloaded the tool with which it was equipped in a position of the tool magazine.
According to a preferred embodiment of the present invention, the aforesaid oscillating drawer is manually controlled. On the side of the drawer, which always remains outside the protection wall, there is preferably provided a handle for gripping. The aforementioned tool-bearing means with which the door is equipped can be made, in a way in itself known, in the form of elastic grippers or clamps, which ensure temporary stable support of the tool until it is clamped by the spindle of the machining head and removed form the said grippers.